The purpose of this research project is to develop a risk adjustment model that can be applied in pediatric patients with acquired brain injury when they present for pediatric rehabilitation. Patients with acute brain injury admitted for pediatric rehabilitation are a very heterogeneous population with substantial variation in age, nature of brain injury, severity of disability, and potential response to therapy. This variation in baseline differences hinders the assessment of therapy in observational and experimental studies and prevents comparisons of the quality of care among pediatric rehabilitation programs. Currently, there are no risk adjustment tools that are known to be valid and reliable for use in patients receiving pediatric rehabilitation after acquired brain injury. This model can then be used in the evaluation of the effectiveness of interventions in experimental and observational studies. It will also facilitate risk-adjusted evaluation of pediatric rehabilitation programs.